Abstract
Stress corrosion cracking of hydrogenated austenitic stainless steels were investigated in H2SO4-NaCl solution. The specimens used were exposed to 280 atm hydrogen at 400°C for 16 hours. The time-to-fracture of hydrogenated Type 304 steel was shorter than that of hydrogen-free ones in weakly corrosive solution and was longer than that of hydrogen-free ones in strongly corrosive solution. And that of hydrogenated Type 316 steel was shorter than that of hydrogen-free ones even in strongly corrosive solution. The susceptibility of stress corrosion cracking of hydrogenated Type 304 steel decreased under the catholic charging. This suggests that the stress corrosion process of this steel is active path corrosion. The self-activation time of Type 304 and 316 steels in H2SO4 solution became shorter by hydrogenation, and cold working increased this trend. In immersion test in FeCl3 solution, Type 304 and 316 steels increased the susceptibility of pitting corrosion by hydrogenation. From these results, the change of stress corrosion cracking susceptibility of hydrogenated austenitic stainless steels might be produced by passive film destabilization and anodic activation of stress induced martensites.
